verify: lots of refactoring - simplify finding first bad rev - no need to count changesets - add exc function to simplify exception handling - combine checksize and checkversion to checklog - unify missing revlog detection in checklog - add checkentry to consolidate - linkrev lookup - detailed check of linkrev - detailed check of parents - duplicate checking - use checkentry for changelog, manifest, and files - simplify havecl and havemf - track all changesets refering to a manifest - move unnamed file check somewhere more useful - reorder crosschecks - fix filenodes crosscheck and add exception handling - check unpacked size field